drivers/target/loopback/tcm_loop.c

   1 /*******************************************************************************
   2  *
   3  * This file contains the Linux/SCSI LLD virtual SCSI initiator driver
   4  * for emulated SAS initiator ports
   5  *
   6  * © Copyright 2011 RisingTide Systems LLC.
   7  *
   8  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
   9  *
  10  * Author: Nicholas A. Bellinger <nab@risingtidesystems.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  ****************************************************************************/
  22
  23 #include <linux/module.h>
  24 #include <linux/moduleparam.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/types.h>
  28 #include <linux/configfs.h>
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_cmnd.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_fabric.h>
  37 #include <target/target_core_fabric_configfs.h>
  38 #include <target/target_core_configfs.h>
  39
  40 #include "tcm_loop.h"
  41
  42 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
  43
  44 /* Local pointer to allocated TCM configfs fabric module */
  45 static struct target_fabric_configfs *tcm_loop_fabric_configfs;
  46
  47 static struct kmem_cache *tcm_loop_cmd_cache;
  48
  49 static int tcm_loop_hba_no_cnt;
  50
  51 /*
  52  * Allocate a tcm_loop cmd descriptor from target_core_mod code
  53  *
  54  * Can be called from interrupt context in tcm_loop_queuecommand() below
  55  */
  56 static struct se_cmd *tcm_loop_allocate_core_cmd(
  57         struct tcm_loop_hba *tl_hba,
  58         struct se_portal_group *se_tpg,
  59         struct scsi_cmnd *sc)
  60 {
  61         struct se_cmd *se_cmd;
  62         struct se_session *se_sess;
  63         struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
  64         struct tcm_loop_cmd *tl_cmd;
  65         int sam_task_attr;
  66
  67         if (!tl_nexus) {
  68                 scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
  69                                 " does not exist\n");
  70                 set_host_byte(sc, DID_ERROR);
  71                 return NULL;
  72         }
  73         se_sess = tl_nexus->se_sess;
  74
  75         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
  76         if (!tl_cmd) {
  77                 pr_err("Unable to allocate struct tcm_loop_cmd\n");
  78                 set_host_byte(sc, DID_ERROR);
  79                 return NULL;
  80         }
  81         se_cmd = &tl_cmd->tl_se_cmd;
  82         /*
  83          * Save the pointer to struct scsi_cmnd *sc
  84          */
  85         tl_cmd->sc = sc;
  86         /*
  87          * Locate the SAM Task Attr from struct scsi_cmnd *
  88          */
  89         if (sc->device->tagged_supported) {
  90                 switch (sc->tag) {
  91                 case HEAD_OF_QUEUE_TAG:
  92                         sam_task_attr = MSG_HEAD_TAG;
  93                         break;
  94                 case ORDERED_QUEUE_TAG:
  95                         sam_task_attr = MSG_ORDERED_TAG;
  96                         break;
  97                 default:
  98                         sam_task_attr = MSG_SIMPLE_TAG;
  99                         break;
 100                 }
 101         } else
 102                 sam_task_attr = MSG_SIMPLE_TAG;
 103
 104         /*
 105          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 106          */
 107         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
 108                         scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
 109                         &tl_cmd->tl_sense_buf[0]);
 110
 111         if (scsi_bidi_cmnd(sc))
 112                 se_cmd->se_cmd_flags |= SCF_BIDI;
 113
 114         /*
 115          * Locate the struct se_lun pointer and attach it to struct se_cmd
 116          */
 117         if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
 118                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 119                 set_host_byte(sc, DID_NO_CONNECT);
 120                 return NULL;
 121         }
 122
 123         return se_cmd;
 124 }
 125
 126 /*
 127  * Called by struct target_core_fabric_ops->new_cmd_map()
 128  *
 129  * Always called in process context.  A non zero return value
 130  * here will signal to handle an exception based on the return code.
 131  */
 132 static int tcm_loop_new_cmd_map(struct se_cmd *se_cmd)
 133 {
 134         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 135                                 struct tcm_loop_cmd, tl_se_cmd);
 136         struct scsi_cmnd *sc = tl_cmd->sc;
 137         struct scatterlist *sgl_bidi = NULL;
 138         u32 sgl_bidi_count = 0;
 139         int ret;
 140         /*
 141          * Allocate the necessary tasks to complete the received CDB+data
 142          */
 143         ret = transport_generic_allocate_tasks(se_cmd, sc->cmnd);
 144         if (ret != 0)
 145                 return ret;
 146         /*
 147          * For BIDI commands, pass in the extra READ buffer
 148          * to transport_generic_map_mem_to_cmd() below..
 149          */
 150         if (se_cmd->se_cmd_flags & SCF_BIDI) {
 151                 struct scsi_data_buffer *sdb = scsi_in(sc);
 152
 153                 sgl_bidi = sdb->table.sgl;
 154                 sgl_bidi_count = sdb->table.nents;
 155         }
 156         /*
 157          * Because some userspace code via scsi-generic do not memset their
 158          * associated read buffers, go ahead and do that here for type
 159          * SCF_SCSI_CONTROL_SG_IO_CDB.  Also note that this is currently
 160          * guaranteed to be a single SGL for SCF_SCSI_CONTROL_SG_IO_CDB
 161          * by target core in transport_generic_allocate_tasks() ->
 162          * transport_generic_cmd_sequencer().
 163          */
 164         if (se_cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB &&
 165             se_cmd->data_direction == DMA_FROM_DEVICE) {
 166                 struct scatterlist *sg = scsi_sglist(sc);
 167                 unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
 168
 169                 if (buf != NULL) {
 170                         memset(buf, 0, sg->length);
 171                         kunmap(sg_page(sg));
 172                 }
 173         }
 174
 175         /* Tell the core about our preallocated memory */
 176         return transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
 177                         scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
 178 }
 179
 180 /*
 181  * Called from struct target_core_fabric_ops->check_stop_free()
 182  */
 183 static int tcm_loop_check_stop_free(struct se_cmd *se_cmd)
 184 {
 185         /*
 186          * Do not release struct se_cmd's containing a valid TMR
 187          * pointer.  These will be released directly in tcm_loop_device_reset()
 188          * with transport_generic_free_cmd().
 189          */
 190         if (se_cmd->se_tmr_req)
 191                 return 0;
 192         /*
 193          * Release the struct se_cmd, which will make a callback to release
 194          * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd()
 195          */
 196         transport_generic_free_cmd(se_cmd, 0);
 197         return 1;
 198 }
 199
 200 static void tcm_loop_release_cmd(struct se_cmd *se_cmd)
 201 {
 202         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 203                                 struct tcm_loop_cmd, tl_se_cmd);
 204
 205         kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 206 }
 207
 208 static int tcm_loop_proc_info(struct Scsi_Host *host, char *buffer,
 209                                 char **start, off_t offset,
 210                                 int length, int inout)
 211 {
 212         return sprintf(buffer, "tcm_loop_proc_info()\n");
 213 }
 214
 215 static int tcm_loop_driver_probe(struct device *);
 216 static int tcm_loop_driver_remove(struct device *);
 217
 218 static int pseudo_lld_bus_match(struct device *dev,
 219                                 struct device_driver *dev_driver)
 220 {
 221         return 1;
 222 }
 223
 224 static struct bus_type tcm_loop_lld_bus = {
 225         .name                   = "tcm_loop_bus",
 226         .match                  = pseudo_lld_bus_match,
 227         .probe                  = tcm_loop_driver_probe,
 228         .remove                 = tcm_loop_driver_remove,
 229 };
 230
 231 static struct device_driver tcm_loop_driverfs = {
 232         .name                   = "tcm_loop",
 233         .bus                    = &tcm_loop_lld_bus,
 234 };
 235 /*
 236  * Used with root_device_register() in tcm_loop_alloc_core_bus() below
 237  */
 238 struct device *tcm_loop_primary;
 239
 240 /*
 241  * Copied from drivers/scsi/libfc/fc_fcp.c:fc_change_queue_depth() and
 242  * drivers/scsi/libiscsi.c:iscsi_change_queue_depth()
 243  */
 244 static int tcm_loop_change_queue_depth(
 245         struct scsi_device *sdev,
 246         int depth,
 247         int reason)
 248 {
 249         switch (reason) {
 250         case SCSI_QDEPTH_DEFAULT:
 251                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 252                 break;
 253         case SCSI_QDEPTH_QFULL:
 254                 scsi_track_queue_full(sdev, depth);
 255                 break;
 256         case SCSI_QDEPTH_RAMP_UP:
 257                 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 258                 break;
 259         default:
 260                 return -EOPNOTSUPP;
 261         }
 262         return sdev->queue_depth;
 263 }
 264
 265 /*
 266  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
 267  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
 268  */
 269 static int tcm_loop_queuecommand(
 270         struct Scsi_Host *sh,
 271         struct scsi_cmnd *sc)
 272 {
 273         struct se_cmd *se_cmd;
 274         struct se_portal_group *se_tpg;
 275         struct tcm_loop_hba *tl_hba;
 276         struct tcm_loop_tpg *tl_tpg;
 277
 278         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
 279                 " scsi_buf_len: %u\n", sc->device->host->host_no,
 280                 sc->device->id, sc->device->channel, sc->device->lun,
 281                 sc->cmnd[0], scsi_bufflen(sc));
 282         /*
 283          * Locate the tcm_loop_hba_t pointer
 284          */
 285         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 286         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 287         /*
 288          * Ensure that this tl_tpg reference from the incoming sc->device->id
 289          * has already been configured via tcm_loop_make_naa_tpg().
 290          */
 291         if (!tl_tpg->tl_hba) {
 292                 set_host_byte(sc, DID_NO_CONNECT);
 293                 sc->scsi_done(sc);
 294                 return 0;
 295         }
 296         se_tpg = &tl_tpg->tl_se_tpg;
 297         /*
 298          * Determine the SAM Task Attribute and allocate tl_cmd and
 299          * tl_cmd->tl_se_cmd from TCM infrastructure
 300          */
 301         se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
 302         if (!se_cmd) {
 303                 sc->scsi_done(sc);
 304                 return 0;
 305         }
 306         /*
 307          * Queue up the newly allocated to be processed in TCM thread context.
 308         */
 309         transport_generic_handle_cdb_map(se_cmd);
 310         return 0;
 311 }
 312
 313 /*
 314  * Called from SCSI EH process context to issue a LUN_RESET TMR
 315  * to struct scsi_device
 316  */
 317 static int tcm_loop_device_reset(struct scsi_cmnd *sc)
 318 {
 319         struct se_cmd *se_cmd = NULL;
 320         struct se_portal_group *se_tpg;
 321         struct se_session *se_sess;
 322         struct tcm_loop_cmd *tl_cmd = NULL;
 323         struct tcm_loop_hba *tl_hba;
 324         struct tcm_loop_nexus *tl_nexus;
 325         struct tcm_loop_tmr *tl_tmr = NULL;
 326         struct tcm_loop_tpg *tl_tpg;
 327         int ret = FAILED;
 328         /*
 329          * Locate the tcm_loop_hba_t pointer
 330          */
 331         tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
 332         /*
 333          * Locate the tl_nexus and se_sess pointers
 334          */
 335         tl_nexus = tl_hba->tl_nexus;
 336         if (!tl_nexus) {
 337                 pr_err("Unable to perform device reset without"
 338                                 " active I_T Nexus\n");
 339                 return FAILED;
 340         }
 341         se_sess = tl_nexus->se_sess;
 342         /*
 343          * Locate the tl_tpg and se_tpg pointers from TargetID in sc->device->id
 344          */
 345         tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
 346         se_tpg = &tl_tpg->tl_se_tpg;
 347
 348         tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_KERNEL);
 349         if (!tl_cmd) {
 350                 pr_err("Unable to allocate memory for tl_cmd\n");
 351                 return FAILED;
 352         }
 353
 354         tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL);
 355         if (!tl_tmr) {
 356                 pr_err("Unable to allocate memory for tl_tmr\n");
 357                 goto release;
 358         }
 359         init_waitqueue_head(&tl_tmr->tl_tmr_wait);
 360
 361         se_cmd = &tl_cmd->tl_se_cmd;
 362         /*
 363          * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 364          */
 365         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 366                                 DMA_NONE, MSG_SIMPLE_TAG,
 367                                 &tl_cmd->tl_sense_buf[0]);
 368         /*
 369          * Allocate the LUN_RESET TMR
 370          */
 371         se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
 372                                                 TMR_LUN_RESET, GFP_KERNEL);
 373         if (IS_ERR(se_cmd->se_tmr_req))
 374                 goto release;
 375         /*
 376          * Locate the underlying TCM struct se_lun from sc->device->lun
 377          */
 378         if (transport_lookup_tmr_lun(se_cmd, sc->device->lun) < 0)
 379                 goto release;
 380         /*
 381          * Queue the TMR to TCM Core and sleep waiting for tcm_loop_queue_tm_rsp()
 382          * to wake us up.
 383          */
 384         transport_generic_handle_tmr(se_cmd);
 385         wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete));
 386         /*
 387          * The TMR LUN_RESET has completed, check the response status and
 388          * then release allocations.
 389          */
 390         ret = (se_cmd->se_tmr_req->response == TMR_FUNCTION_COMPLETE) ?
 391                 SUCCESS : FAILED;
 392 release:
 393         if (se_cmd)
 394                 transport_generic_free_cmd(se_cmd, 1);
 395         else
 396                 kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
 397         kfree(tl_tmr);
 398         return ret;
 399 }
 400
 401 static int tcm_loop_slave_alloc(struct scsi_device *sd)
 402 {
 403         set_bit(QUEUE_FLAG_BIDI, &sd->request_queue->queue_flags);
 404         return 0;
 405 }
 406
 407 static int tcm_loop_slave_configure(struct scsi_device *sd)
 408 {
 409         return 0;
 410 }
 411
 412 static struct scsi_host_template tcm_loop_driver_template = {
 413         .proc_info              = tcm_loop_proc_info,
 414         .proc_name              = "tcm_loopback",
 415         .name                   = "TCM_Loopback",
 416         .queuecommand           = tcm_loop_queuecommand,
 417         .change_queue_depth     = tcm_loop_change_queue_depth,
 418         .eh_device_reset_handler = tcm_loop_device_reset,
 419         .can_queue              = TL_SCSI_CAN_QUEUE,
 420         .this_id                = -1,
 421         .sg_tablesize           = TL_SCSI_SG_TABLESIZE,
 422         .cmd_per_lun            = TL_SCSI_CMD_PER_LUN,
 423         .max_sectors            = TL_SCSI_MAX_SECTORS,
 424         .use_clustering         = DISABLE_CLUSTERING,
 425         .slave_alloc            = tcm_loop_slave_alloc,
 426         .slave_configure        = tcm_loop_slave_configure,
 427         .module                 = THIS_MODULE,
 428 };
 429
 430 static int tcm_loop_driver_probe(struct device *dev)
 431 {
 432         struct tcm_loop_hba *tl_hba;
 433         struct Scsi_Host *sh;
 434         int error;
 435
 436         tl_hba = to_tcm_loop_hba(dev);
 437
 438         sh = scsi_host_alloc(&tcm_loop_driver_template,
 439                         sizeof(struct tcm_loop_hba));
 440         if (!sh) {
 441                 pr_err("Unable to allocate struct scsi_host\n");
 442                 return -ENODEV;
 443         }
 444         tl_hba->sh = sh;
 445
 446         /*
 447          * Assign the struct tcm_loop_hba pointer to struct Scsi_Host->hostdata
 448          */
 449         *((struct tcm_loop_hba **)sh->hostdata) = tl_hba;
 450         /*
 451          * Setup single ID, Channel and LUN for now..
 452          */
 453         sh->max_id = 2;
 454         sh->max_lun = 0;
 455         sh->max_channel = 0;
 456         sh->max_cmd_len = TL_SCSI_MAX_CMD_LEN;
 457
 458         error = scsi_add_host(sh, &tl_hba->dev);
 459         if (error) {
 460                 pr_err("%s: scsi_add_host failed\n", __func__);
 461                 scsi_host_put(sh);
 462                 return -ENODEV;
 463         }
 464         return 0;
 465 }
 466
 467 static int tcm_loop_driver_remove(struct device *dev)
 468 {
 469         struct tcm_loop_hba *tl_hba;
 470         struct Scsi_Host *sh;
 471
 472         tl_hba = to_tcm_loop_hba(dev);
 473         sh = tl_hba->sh;
 474
 475         scsi_remove_host(sh);
 476         scsi_host_put(sh);
 477         return 0;
 478 }
 479
 480 static void tcm_loop_release_adapter(struct device *dev)
 481 {
 482         struct tcm_loop_hba *tl_hba = to_tcm_loop_hba(dev);
 483
 484         kfree(tl_hba);
 485 }
 486
 487 /*
 488  * Called from tcm_loop_make_scsi_hba() in tcm_loop_configfs.c
 489  */
 490 static int tcm_loop_setup_hba_bus(struct tcm_loop_hba *tl_hba, int tcm_loop_host_id)
 491 {
 492         int ret;
 493
 494         tl_hba->dev.bus = &tcm_loop_lld_bus;
 495         tl_hba->dev.parent = tcm_loop_primary;
 496         tl_hba->dev.release = &tcm_loop_release_adapter;
 497         dev_set_name(&tl_hba->dev, "tcm_loop_adapter_%d", tcm_loop_host_id);
 498
 499         ret = device_register(&tl_hba->dev);
 500         if (ret) {
 501                 pr_err("device_register() failed for"
 502                                 " tl_hba->dev: %d\n", ret);
 503                 return -ENODEV;
 504         }
 505
 506         return 0;
 507 }
 508
 509 /*
 510  * Called from tcm_loop_fabric_init() in tcl_loop_fabric.c to load the emulated
 511  * tcm_loop SCSI bus.
 512  */
 513 static int tcm_loop_alloc_core_bus(void)
 514 {
 515         int ret;
 516
 517         tcm_loop_primary = root_device_register("tcm_loop_0");
 518         if (IS_ERR(tcm_loop_primary)) {
 519                 pr_err("Unable to allocate tcm_loop_primary\n");
 520                 return PTR_ERR(tcm_loop_primary);
 521         }
 522
 523         ret = bus_register(&tcm_loop_lld_bus);
 524         if (ret) {
 525                 pr_err("bus_register() failed for tcm_loop_lld_bus\n");
 526                 goto dev_unreg;
 527         }
 528
 529         ret = driver_register(&tcm_loop_driverfs);
 530         if (ret) {
 531                 pr_err("driver_register() failed for"
 532                                 "tcm_loop_driverfs\n");
 533                 goto bus_unreg;
 534         }
 535
 536         pr_debug("Initialized TCM Loop Core Bus\n");
 537         return ret;
 538
 539 bus_unreg:
 540         bus_unregister(&tcm_loop_lld_bus);
 541 dev_unreg:
 542         root_device_unregister(tcm_loop_primary);
 543         return ret;
 544 }
 545
 546 static void tcm_loop_release_core_bus(void)
 547 {
 548         driver_unregister(&tcm_loop_driverfs);
 549         bus_unregister(&tcm_loop_lld_bus);
 550         root_device_unregister(tcm_loop_primary);
 551
 552         pr_debug("Releasing TCM Loop Core BUS\n");
 553 }
 554
 555 static char *tcm_loop_get_fabric_name(void)
 556 {
 557         return "loopback";
 558 }
 559
 560 static u8 tcm_loop_get_fabric_proto_ident(struct se_portal_group *se_tpg)
 561 {
 562         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 563         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 564         /*
 565          * tl_proto_id is set at tcm_loop_configfs.c:tcm_loop_make_scsi_hba()
 566          * time based on the protocol dependent prefix of the passed configfs group.
 567          *
 568          * Based upon tl_proto_id, TCM_Loop emulates the requested fabric
 569          * ProtocolID using target_core_fabric_lib.c symbols.
 570          */
 571         switch (tl_hba->tl_proto_id) {
 572         case SCSI_PROTOCOL_SAS:
 573                 return sas_get_fabric_proto_ident(se_tpg);
 574         case SCSI_PROTOCOL_FCP:
 575                 return fc_get_fabric_proto_ident(se_tpg);
 576         case SCSI_PROTOCOL_ISCSI:
 577                 return iscsi_get_fabric_proto_ident(se_tpg);
 578         default:
 579                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 580                         " SAS emulation\n", tl_hba->tl_proto_id);
 581                 break;
 582         }
 583
 584         return sas_get_fabric_proto_ident(se_tpg);
 585 }
 586
 587 static char *tcm_loop_get_endpoint_wwn(struct se_portal_group *se_tpg)
 588 {
 589         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 590         /*
 591          * Return the passed NAA identifier for the SAS Target Port
 592          */
 593         return &tl_tpg->tl_hba->tl_wwn_address[0];
 594 }
 595
 596 static u16 tcm_loop_get_tag(struct se_portal_group *se_tpg)
 597 {
 598         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 599         /*
 600          * This Tag is used when forming SCSI Name identifier in EVPD=1 0x83
 601          * to represent the SCSI Target Port.
 602          */
 603         return tl_tpg->tl_tpgt;
 604 }
 605
 606 static u32 tcm_loop_get_default_depth(struct se_portal_group *se_tpg)
 607 {
 608         return 1;
 609 }
 610
 611 static u32 tcm_loop_get_pr_transport_id(
 612         struct se_portal_group *se_tpg,
 613         struct se_node_acl *se_nacl,
 614         struct t10_pr_registration *pr_reg,
 615         int *format_code,
 616         unsigned char *buf)
 617 {
 618         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 619         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 620
 621         switch (tl_hba->tl_proto_id) {
 622         case SCSI_PROTOCOL_SAS:
 623                 return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 624                                         format_code, buf);
 625         case SCSI_PROTOCOL_FCP:
 626                 return fc_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 627                                         format_code, buf);
 628         case SCSI_PROTOCOL_ISCSI:
 629                 return iscsi_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 630                                         format_code, buf);
 631         default:
 632                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 633                         " SAS emulation\n", tl_hba->tl_proto_id);
 634                 break;
 635         }
 636
 637         return sas_get_pr_transport_id(se_tpg, se_nacl, pr_reg,
 638                         format_code, buf);
 639 }
 640
 641 static u32 tcm_loop_get_pr_transport_id_len(
 642         struct se_portal_group *se_tpg,
 643         struct se_node_acl *se_nacl,
 644         struct t10_pr_registration *pr_reg,
 645         int *format_code)
 646 {
 647         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 648         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 649
 650         switch (tl_hba->tl_proto_id) {
 651         case SCSI_PROTOCOL_SAS:
 652                 return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 653                                         format_code);
 654         case SCSI_PROTOCOL_FCP:
 655                 return fc_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 656                                         format_code);
 657         case SCSI_PROTOCOL_ISCSI:
 658                 return iscsi_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 659                                         format_code);
 660         default:
 661                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 662                         " SAS emulation\n", tl_hba->tl_proto_id);
 663                 break;
 664         }
 665
 666         return sas_get_pr_transport_id_len(se_tpg, se_nacl, pr_reg,
 667                         format_code);
 668 }
 669
 670 /*
 671  * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 672  * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 673  */
 674 static char *tcm_loop_parse_pr_out_transport_id(
 675         struct se_portal_group *se_tpg,
 676         const char *buf,
 677         u32 *out_tid_len,
 678         char **port_nexus_ptr)
 679 {
 680         struct tcm_loop_tpg *tl_tpg = se_tpg->se_tpg_fabric_ptr;
 681         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 682
 683         switch (tl_hba->tl_proto_id) {
 684         case SCSI_PROTOCOL_SAS:
 685                 return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 686                                         port_nexus_ptr);
 687         case SCSI_PROTOCOL_FCP:
 688                 return fc_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 689                                         port_nexus_ptr);
 690         case SCSI_PROTOCOL_ISCSI:
 691                 return iscsi_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 692                                         port_nexus_ptr);
 693         default:
 694                 pr_err("Unknown tl_proto_id: 0x%02x, using"
 695                         " SAS emulation\n", tl_hba->tl_proto_id);
 696                 break;
 697         }
 698
 699         return sas_parse_pr_out_transport_id(se_tpg, buf, out_tid_len,
 700                         port_nexus_ptr);
 701 }
 702
 703 /*
 704  * Returning (1) here allows for target_core_mod struct se_node_acl to be generated
 705  * based upon the incoming fabric dependent SCSI Initiator Port
 706  */
 707 static int tcm_loop_check_demo_mode(struct se_portal_group *se_tpg)
 708 {
 709         return 1;
 710 }
 711
 712 static int tcm_loop_check_demo_mode_cache(struct se_portal_group *se_tpg)
 713 {
 714         return 0;
 715 }
 716
 717 /*
 718  * Allow I_T Nexus full READ-WRITE access without explict Initiator Node ACLs for
 719  * local virtual Linux/SCSI LLD passthrough into VM hypervisor guest
 720  */
 721 static int tcm_loop_check_demo_mode_write_protect(struct se_portal_group *se_tpg)
 722 {
 723         return 0;
 724 }
 725
 726 /*
 727  * Because TCM_Loop does not use explict ACLs and MappedLUNs, this will
 728  * never be called for TCM_Loop by target_core_fabric_configfs.c code.
 729  * It has been added here as a nop for target_fabric_tf_ops_check()
 730  */
 731 static int tcm_loop_check_prod_mode_write_protect(struct se_portal_group *se_tpg)
 732 {
 733         return 0;
 734 }
 735
 736 static struct se_node_acl *tcm_loop_tpg_alloc_fabric_acl(
 737         struct se_portal_group *se_tpg)
 738 {
 739         struct tcm_loop_nacl *tl_nacl;
 740
 741         tl_nacl = kzalloc(sizeof(struct tcm_loop_nacl), GFP_KERNEL);
 742         if (!tl_nacl) {
 743                 pr_err("Unable to allocate struct tcm_loop_nacl\n");
 744                 return NULL;
 745         }
 746
 747         return &tl_nacl->se_node_acl;
 748 }
 749
 750 static void tcm_loop_tpg_release_fabric_acl(
 751         struct se_portal_group *se_tpg,
 752         struct se_node_acl *se_nacl)
 753 {
 754         struct tcm_loop_nacl *tl_nacl = container_of(se_nacl,
 755                                 struct tcm_loop_nacl, se_node_acl);
 756
 757         kfree(tl_nacl);
 758 }
 759
 760 static u32 tcm_loop_get_inst_index(struct se_portal_group *se_tpg)
 761 {
 762         return 1;
 763 }
 764
 765 static int tcm_loop_is_state_remove(struct se_cmd *se_cmd)
 766 {
 767         /*
 768          * Assume struct scsi_cmnd is not in remove state..
 769          */
 770         return 0;
 771 }
 772
 773 static int tcm_loop_sess_logged_in(struct se_session *se_sess)
 774 {
 775         /*
 776          * Assume that TL Nexus is always active
 777          */
 778         return 1;
 779 }
 780
 781 static u32 tcm_loop_sess_get_index(struct se_session *se_sess)
 782 {
 783         return 1;
 784 }
 785
 786 static void tcm_loop_set_default_node_attributes(struct se_node_acl *se_acl)
 787 {
 788         return;
 789 }
 790
 791 static u32 tcm_loop_get_task_tag(struct se_cmd *se_cmd)
 792 {
 793         return 1;
 794 }
 795
 796 static int tcm_loop_get_cmd_state(struct se_cmd *se_cmd)
 797 {
 798         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 799                         struct tcm_loop_cmd, tl_se_cmd);
 800
 801         return tl_cmd->sc_cmd_state;
 802 }
 803
 804 static int tcm_loop_shutdown_session(struct se_session *se_sess)
 805 {
 806         return 0;
 807 }
 808
 809 static void tcm_loop_close_session(struct se_session *se_sess)
 810 {
 811         return;
 812 };
 813
 814 static void tcm_loop_stop_session(
 815         struct se_session *se_sess,
 816         int sess_sleep,
 817         int conn_sleep)
 818 {
 819         return;
 820 }
 821
 822 static void tcm_loop_fall_back_to_erl0(struct se_session *se_sess)
 823 {
 824         return;
 825 }
 826
 827 static int tcm_loop_write_pending(struct se_cmd *se_cmd)
 828 {
 829         /*
 830          * Since Linux/SCSI has already sent down a struct scsi_cmnd
 831          * sc->sc_data_direction of DMA_TO_DEVICE with struct scatterlist array
 832          * memory, and memory has already been mapped to struct se_cmd->t_mem_list
 833          * format with transport_generic_map_mem_to_cmd().
 834          *
 835          * We now tell TCM to add this WRITE CDB directly into the TCM storage
 836          * object execution queue.
 837          */
 838         transport_generic_process_write(se_cmd);
 839         return 0;
 840 }
 841
 842 static int tcm_loop_write_pending_status(struct se_cmd *se_cmd)
 843 {
 844         return 0;
 845 }
 846
 847 static int tcm_loop_queue_data_in(struct se_cmd *se_cmd)
 848 {
 849         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 850                                 struct tcm_loop_cmd, tl_se_cmd);
 851         struct scsi_cmnd *sc = tl_cmd->sc;
 852
 853         pr_debug("tcm_loop_queue_data_in() called for scsi_cmnd: %p"
 854                      " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 855
 856         sc->result = SAM_STAT_GOOD;
 857         set_host_byte(sc, DID_OK);
 858         sc->scsi_done(sc);
 859         return 0;
 860 }
 861
 862 static int tcm_loop_queue_status(struct se_cmd *se_cmd)
 863 {
 864         struct tcm_loop_cmd *tl_cmd = container_of(se_cmd,
 865                                 struct tcm_loop_cmd, tl_se_cmd);
 866         struct scsi_cmnd *sc = tl_cmd->sc;
 867
 868         pr_debug("tcm_loop_queue_status() called for scsi_cmnd: %p"
 869                         " cdb: 0x%02x\n", sc, sc->cmnd[0]);
 870
 871         if (se_cmd->sense_buffer &&
 872            ((se_cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
 873             (se_cmd->se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
 874
 875                 memcpy(sc->sense_buffer, se_cmd->sense_buffer,
 876                                 SCSI_SENSE_BUFFERSIZE);
 877                 sc->result = SAM_STAT_CHECK_CONDITION;
 878                 set_driver_byte(sc, DRIVER_SENSE);
 879         } else
 880                 sc->result = se_cmd->scsi_status;
 881
 882         set_host_byte(sc, DID_OK);
 883         sc->scsi_done(sc);
 884         return 0;
 885 }
 886
 887 static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 888 {
 889         struct se_tmr_req *se_tmr = se_cmd->se_tmr_req;
 890         struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr;
 891         /*
 892          * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead
 893          * and wake up the wait_queue_head_t in tcm_loop_device_reset()
 894          */
 895         atomic_set(&tl_tmr->tmr_complete, 1);
 896         wake_up(&tl_tmr->tl_tmr_wait);
 897         return 0;
 898 }
 899
 900 static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
 901 {
 902         return 0;
 903 }
 904
 905 static u16 tcm_loop_get_fabric_sense_len(void)
 906 {
 907         return 0;
 908 }
 909
 910 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 911 {
 912         switch (tl_hba->tl_proto_id) {
 913         case SCSI_PROTOCOL_SAS:
 914                 return "SAS";
 915         case SCSI_PROTOCOL_FCP:
 916                 return "FCP";
 917         case SCSI_PROTOCOL_ISCSI:
 918                 return "iSCSI";
 919         default:
 920                 break;
 921         }
 922
 923         return "Unknown";
 924 }
 925
 926 /* Start items for tcm_loop_port_cit */
 927
 928 static int tcm_loop_port_link(
 929         struct se_portal_group *se_tpg,
 930         struct se_lun *lun)
 931 {
 932         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
 933                                 struct tcm_loop_tpg, tl_se_tpg);
 934         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 935
 936         atomic_inc(&tl_tpg->tl_tpg_port_count);
 937         smp_mb__after_atomic_inc();
 938         /*
 939          * Add Linux/SCSI struct scsi_device by HCTL
 940          */
 941         scsi_add_device(tl_hba->sh, 0, tl_tpg->tl_tpgt, lun->unpacked_lun);
 942
 943         pr_debug("TCM_Loop_ConfigFS: Port Link Successful\n");
 944         return 0;
 945 }
 946
 947 static void tcm_loop_port_unlink(
 948         struct se_portal_group *se_tpg,
 949         struct se_lun *se_lun)
 950 {
 951         struct scsi_device *sd;
 952         struct tcm_loop_hba *tl_hba;
 953         struct tcm_loop_tpg *tl_tpg;
 954
 955         tl_tpg = container_of(se_tpg, struct tcm_loop_tpg, tl_se_tpg);
 956         tl_hba = tl_tpg->tl_hba;
 957
 958         sd = scsi_device_lookup(tl_hba->sh, 0, tl_tpg->tl_tpgt,
 959                                 se_lun->unpacked_lun);
 960         if (!sd) {
 961                 pr_err("Unable to locate struct scsi_device for %d:%d:"
 962                         "%d\n", 0, tl_tpg->tl_tpgt, se_lun->unpacked_lun);
 963                 return;
 964         }
 965         /*
 966          * Remove Linux/SCSI struct scsi_device by HCTL
 967          */
 968         scsi_remove_device(sd);
 969         scsi_device_put(sd);
 970
 971         atomic_dec(&tl_tpg->tl_tpg_port_count);
 972         smp_mb__after_atomic_dec();
 973
 974         pr_debug("TCM_Loop_ConfigFS: Port Unlink Successful\n");
 975 }
 976
 977 /* End items for tcm_loop_port_cit */
 978
 979 /* Start items for tcm_loop_nexus_cit */
 980
 981 static int tcm_loop_make_nexus(
 982         struct tcm_loop_tpg *tl_tpg,
 983         const char *name)
 984 {
 985         struct se_portal_group *se_tpg;
 986         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 987         struct tcm_loop_nexus *tl_nexus;
 988         int ret = -ENOMEM;
 989
 990         if (tl_tpg->tl_hba->tl_nexus) {
 991                 pr_debug("tl_tpg->tl_hba->tl_nexus already exists\n");
 992                 return -EEXIST;
 993         }
 994         se_tpg = &tl_tpg->tl_se_tpg;
 995
 996         tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
 997         if (!tl_nexus) {
 998                 pr_err("Unable to allocate struct tcm_loop_nexus\n");
 999                 return -ENOMEM;
1000         }
1001         /*
1002          * Initialize the struct se_session pointer
1003          */
1004         tl_nexus->se_sess = transport_init_session();
1005         if (IS_ERR(tl_nexus->se_sess)) {
1006                 ret = PTR_ERR(tl_nexus->se_sess);
1007                 goto out;
1008         }
1009         /*
1010          * Since we are running in 'demo mode' this call with generate a
1011          * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
1012          * Initiator port name of the passed configfs group 'name'.
1013          */
1014         tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
1015                                 se_tpg, (unsigned char *)name);
1016         if (!tl_nexus->se_sess->se_node_acl) {
1017                 transport_free_session(tl_nexus->se_sess);
1018                 goto out;
1019         }
1020         /*
1021          * Now, register the SAS I_T Nexus as active with the call to
1022          * transport_register_session()
1023          */
1024         __transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
1025                         tl_nexus->se_sess, tl_nexus);
1026         tl_tpg->tl_hba->tl_nexus = tl_nexus;
1027         pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
1028                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1029                 name);
1030         return 0;
1031
1032 out:
1033         kfree(tl_nexus);
1034         return ret;
1035 }
1036
1037 static int tcm_loop_drop_nexus(
1038         struct tcm_loop_tpg *tpg)
1039 {
1040         struct se_session *se_sess;
1041         struct tcm_loop_nexus *tl_nexus;
1042         struct tcm_loop_hba *tl_hba = tpg->tl_hba;
1043
1044         tl_nexus = tpg->tl_hba->tl_nexus;
1045         if (!tl_nexus)
1046                 return -ENODEV;
1047
1048         se_sess = tl_nexus->se_sess;
1049         if (!se_sess)
1050                 return -ENODEV;
1051
1052         if (atomic_read(&tpg->tl_tpg_port_count)) {
1053                 pr_err("Unable to remove TCM_Loop I_T Nexus with"
1054                         " active TPG port count: %d\n",
1055                         atomic_read(&tpg->tl_tpg_port_count));
1056                 return -EPERM;
1057         }
1058
1059         pr_debug("TCM_Loop_ConfigFS: Removing I_T Nexus to emulated"
1060                 " %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
1061                 tl_nexus->se_sess->se_node_acl->initiatorname);
1062         /*
1063          * Release the SCSI I_T Nexus to the emulated SAS Target Port
1064          */
1065         transport_deregister_session(tl_nexus->se_sess);
1066         tpg->tl_hba->tl_nexus = NULL;
1067         kfree(tl_nexus);
1068         return 0;
1069 }
1070
1071 /* End items for tcm_loop_nexus_cit */
1072
1073 static ssize_t tcm_loop_tpg_show_nexus(
1074         struct se_portal_group *se_tpg,
1075         char *page)
1076 {
1077         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1078                         struct tcm_loop_tpg, tl_se_tpg);
1079         struct tcm_loop_nexus *tl_nexus;
1080         ssize_t ret;
1081
1082         tl_nexus = tl_tpg->tl_hba->tl_nexus;
1083         if (!tl_nexus)
1084                 return -ENODEV;
1085
1086         ret = snprintf(page, PAGE_SIZE, "%s\n",
1087                 tl_nexus->se_sess->se_node_acl->initiatorname);
1088
1089         return ret;
1090 }
1091
1092 static ssize_t tcm_loop_tpg_store_nexus(
1093         struct se_portal_group *se_tpg,
1094         const char *page,
1095         size_t count)
1096 {
1097         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1098                         struct tcm_loop_tpg, tl_se_tpg);
1099         struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
1100         unsigned char i_port[TL_WWN_ADDR_LEN], *ptr, *port_ptr;
1101         int ret;
1102         /*
1103          * Shutdown the active I_T nexus if 'NULL' is passed..
1104          */
1105         if (!strncmp(page, "NULL", 4)) {
1106                 ret = tcm_loop_drop_nexus(tl_tpg);
1107                 return (!ret) ? count : ret;
1108         }
1109         /*
1110          * Otherwise make sure the passed virtual Initiator port WWN matches
1111          * the fabric protocol_id set in tcm_loop_make_scsi_hba(), and call
1112          * tcm_loop_make_nexus()
1113          */
1114         if (strlen(page) >= TL_WWN_ADDR_LEN) {
1115                 pr_err("Emulated NAA Sas Address: %s, exceeds"
1116                                 " max: %d\n", page, TL_WWN_ADDR_LEN);
1117                 return -EINVAL;
1118         }
1119         snprintf(&i_port[0], TL_WWN_ADDR_LEN, "%s", page);
1120
1121         ptr = strstr(i_port, "naa.");
1122         if (ptr) {
1123                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_SAS) {
1124                         pr_err("Passed SAS Initiator Port %s does not"
1125                                 " match target port protoid: %s\n", i_port,
1126                                 tcm_loop_dump_proto_id(tl_hba));
1127                         return -EINVAL;
1128                 }
1129                 port_ptr = &i_port[0];
1130                 goto check_newline;
1131         }
1132         ptr = strstr(i_port, "fc.");
1133         if (ptr) {
1134                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_FCP) {
1135                         pr_err("Passed FCP Initiator Port %s does not"
1136                                 " match target port protoid: %s\n", i_port,
1137                                 tcm_loop_dump_proto_id(tl_hba));
1138                         return -EINVAL;
1139                 }
1140                 port_ptr = &i_port[3]; /* Skip over "fc." */
1141                 goto check_newline;
1142         }
1143         ptr = strstr(i_port, "iqn.");
1144         if (ptr) {
1145                 if (tl_hba->tl_proto_id != SCSI_PROTOCOL_ISCSI) {
1146                         pr_err("Passed iSCSI Initiator Port %s does not"
1147                                 " match target port protoid: %s\n", i_port,
1148                                 tcm_loop_dump_proto_id(tl_hba));
1149                         return -EINVAL;
1150                 }
1151                 port_ptr = &i_port[0];
1152                 goto check_newline;
1153         }
1154         pr_err("Unable to locate prefix for emulated Initiator Port:"
1155                         " %s\n", i_port);
1156         return -EINVAL;
1157         /*
1158          * Clear any trailing newline for the NAA WWN
1159          */
1160 check_newline:
1161         if (i_port[strlen(i_port)-1] == '\n')
1162                 i_port[strlen(i_port)-1] = '\0';
1163
1164         ret = tcm_loop_make_nexus(tl_tpg, port_ptr);
1165         if (ret < 0)
1166                 return ret;
1167
1168         return count;
1169 }
1170
1171 TF_TPG_BASE_ATTR(tcm_loop, nexus, S_IRUGO | S_IWUSR);
1172
1173 static struct configfs_attribute *tcm_loop_tpg_attrs[] = {
1174         &tcm_loop_tpg_nexus.attr,
1175         NULL,
1176 };
1177
1178 /* Start items for tcm_loop_naa_cit */
1179
1180 struct se_portal_group *tcm_loop_make_naa_tpg(
1181         struct se_wwn *wwn,
1182         struct config_group *group,
1183         const char *name)
1184 {
1185         struct tcm_loop_hba *tl_hba = container_of(wwn,
1186                         struct tcm_loop_hba, tl_hba_wwn);
1187         struct tcm_loop_tpg *tl_tpg;
1188         char *tpgt_str, *end_ptr;
1189         int ret;
1190         unsigned short int tpgt;
1191
1192         tpgt_str = strstr(name, "tpgt_");
1193         if (!tpgt_str) {
1194                 pr_err("Unable to locate \"tpgt_#\" directory"
1195                                 " group\n");
1196                 return ERR_PTR(-EINVAL);
1197         }
1198         tpgt_str += 5; /* Skip ahead of "tpgt_" */
1199         tpgt = (unsigned short int) simple_strtoul(tpgt_str, &end_ptr, 0);
1200
1201         if (tpgt >= TL_TPGS_PER_HBA) {
1202                 pr_err("Passed tpgt: %hu exceeds TL_TPGS_PER_HBA:"
1203                                 " %u\n", tpgt, TL_TPGS_PER_HBA);
1204                 return ERR_PTR(-EINVAL);
1205         }
1206         tl_tpg = &tl_hba->tl_hba_tpgs[tpgt];
1207         tl_tpg->tl_hba = tl_hba;
1208         tl_tpg->tl_tpgt = tpgt;
1209         /*
1210          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
1211          */
1212         ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
1213                         wwn, &tl_tpg->tl_se_tpg, tl_tpg,
1214                         TRANSPORT_TPG_TYPE_NORMAL);
1215         if (ret < 0)
1216                 return ERR_PTR(-ENOMEM);
1217
1218         pr_debug("TCM_Loop_ConfigFS: Allocated Emulated %s"
1219                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1220                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1221
1222         return &tl_tpg->tl_se_tpg;
1223 }
1224
1225 void tcm_loop_drop_naa_tpg(
1226         struct se_portal_group *se_tpg)
1227 {
1228         struct se_wwn *wwn = se_tpg->se_tpg_wwn;
1229         struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
1230                                 struct tcm_loop_tpg, tl_se_tpg);
1231         struct tcm_loop_hba *tl_hba;
1232         unsigned short tpgt;
1233
1234         tl_hba = tl_tpg->tl_hba;
1235         tpgt = tl_tpg->tl_tpgt;
1236         /*
1237          * Release the I_T Nexus for the Virtual SAS link if present
1238          */
1239         tcm_loop_drop_nexus(tl_tpg);
1240         /*
1241          * Deregister the tl_tpg as a emulated SAS TCM Target Endpoint
1242          */
1243         core_tpg_deregister(se_tpg);
1244
1245         tl_tpg->tl_hba = NULL;
1246         tl_tpg->tl_tpgt = 0;
1247
1248         pr_debug("TCM_Loop_ConfigFS: Deallocated Emulated %s"
1249                 " Target Port %s,t,0x%04x\n", tcm_loop_dump_proto_id(tl_hba),
1250                 config_item_name(&wwn->wwn_group.cg_item), tpgt);
1251 }
1252
1253 /* End items for tcm_loop_naa_cit */
1254
1255 /* Start items for tcm_loop_cit */
1256
1257 struct se_wwn *tcm_loop_make_scsi_hba(
1258         struct target_fabric_configfs *tf,
1259         struct config_group *group,
1260         const char *name)
1261 {
1262         struct tcm_loop_hba *tl_hba;
1263         struct Scsi_Host *sh;
1264         char *ptr;
1265         int ret, off = 0;
1266
1267         tl_hba = kzalloc(sizeof(struct tcm_loop_hba), GFP_KERNEL);
1268         if (!tl_hba) {
1269                 pr_err("Unable to allocate struct tcm_loop_hba\n");
1270                 return ERR_PTR(-ENOMEM);
1271         }
1272         /*
1273          * Determine the emulated Protocol Identifier and Target Port Name
1274          * based on the incoming configfs directory name.
1275          */
1276         ptr = strstr(name, "naa.");
1277         if (ptr) {
1278                 tl_hba->tl_proto_id = SCSI_PROTOCOL_SAS;
1279                 goto check_len;
1280         }
1281         ptr = strstr(name, "fc.");
1282         if (ptr) {
1283                 tl_hba->tl_proto_id = SCSI_PROTOCOL_FCP;
1284                 off = 3; /* Skip over "fc." */
1285                 goto check_len;
1286         }
1287         ptr = strstr(name, "iqn.");
1288         if (!ptr) {
1289                 pr_err("Unable to locate prefix for emulated Target "
1290                                 "Port: %s\n", name);
1291                 ret = -EINVAL;
1292                 goto out;
1293         }
1294         tl_hba->tl_proto_id = SCSI_PROTOCOL_ISCSI;
1295
1296 check_len:
1297         if (strlen(name) >= TL_WWN_ADDR_LEN) {
1298                 pr_err("Emulated NAA %s Address: %s, exceeds"
1299                         " max: %d\n", name, tcm_loop_dump_proto_id(tl_hba),
1300                         TL_WWN_ADDR_LEN);
1301                 ret = -EINVAL;
1302                 goto out;
1303         }
1304         snprintf(&tl_hba->tl_wwn_address[0], TL_WWN_ADDR_LEN, "%s", &name[off]);
1305
1306         /*
1307          * Call device_register(tl_hba->dev) to register the emulated
1308          * Linux/SCSI LLD of type struct Scsi_Host at tl_hba->sh after
1309          * device_register() callbacks in tcm_loop_driver_probe()
1310          */
1311         ret = tcm_loop_setup_hba_bus(tl_hba, tcm_loop_hba_no_cnt);
1312         if (ret)
1313                 goto out;
1314
1315         sh = tl_hba->sh;
1316         tcm_loop_hba_no_cnt++;
1317         pr_debug("TCM_Loop_ConfigFS: Allocated emulated Target"
1318                 " %s Address: %s at Linux/SCSI Host ID: %d\n",
1319                 tcm_loop_dump_proto_id(tl_hba), name, sh->host_no);
1320
1321         return &tl_hba->tl_hba_wwn;
1322 out:
1323         kfree(tl_hba);
1324         return ERR_PTR(ret);
1325 }
1326
1327 void tcm_loop_drop_scsi_hba(
1328         struct se_wwn *wwn)
1329 {
1330         struct tcm_loop_hba *tl_hba = container_of(wwn,
1331                                 struct tcm_loop_hba, tl_hba_wwn);
1332
1333         pr_debug("TCM_Loop_ConfigFS: Deallocating emulated Target"
1334                 " SAS Address: %s at Linux/SCSI Host ID: %d\n",
1335                 tl_hba->tl_wwn_address, tl_hba->sh->host_no);
1336         /*
1337          * Call device_unregister() on the original tl_hba->dev.
1338          * tcm_loop_fabric_scsi.c:tcm_loop_release_adapter() will
1339          * release *tl_hba;
1340          */
1341         device_unregister(&tl_hba->dev);
1342 }
1343
1344 /* Start items for tcm_loop_cit */
1345 static ssize_t tcm_loop_wwn_show_attr_version(
1346         struct target_fabric_configfs *tf,
1347         char *page)
1348 {
1349         return sprintf(page, "TCM Loopback Fabric module %s\n", TCM_LOOP_VERSION);
1350 }
1351
1352 TF_WWN_ATTR_RO(tcm_loop, version);
1353
1354 static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
1355         &tcm_loop_wwn_version.attr,
1356         NULL,
1357 };
1358
1359 /* End items for tcm_loop_cit */
1360
1361 static int tcm_loop_register_configfs(void)
1362 {
1363         struct target_fabric_configfs *fabric;
1364         struct config_group *tf_cg;
1365         int ret;
1366         /*
1367          * Set the TCM Loop HBA counter to zero
1368          */
1369         tcm_loop_hba_no_cnt = 0;
1370         /*
1371          * Register the top level struct config_item_type with TCM core
1372          */
1373         fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
1374         if (IS_ERR(fabric)) {
1375                 pr_err("tcm_loop_register_configfs() failed!\n");
1376                 return PTR_ERR(fabric);
1377         }
1378         /*
1379          * Setup the fabric API of function pointers used by target_core_mod
1380          */
1381         fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
1382         fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
1383         fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
1384         fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
1385         fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
1386         fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
1387         fabric->tf_ops.tpg_get_pr_transport_id_len =
1388                                         &tcm_loop_get_pr_transport_id_len;
1389         fabric->tf_ops.tpg_parse_pr_out_transport_id =
1390                                         &tcm_loop_parse_pr_out_transport_id;
1391         fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
1392         fabric->tf_ops.tpg_check_demo_mode_cache =
1393                                         &tcm_loop_check_demo_mode_cache;
1394         fabric->tf_ops.tpg_check_demo_mode_write_protect =
1395                                         &tcm_loop_check_demo_mode_write_protect;
1396         fabric->tf_ops.tpg_check_prod_mode_write_protect =
1397                                         &tcm_loop_check_prod_mode_write_protect;
1398         /*
1399          * The TCM loopback fabric module runs in demo-mode to a local
1400          * virtual SCSI device, so fabric dependent initator ACLs are
1401          * not required.
1402          */
1403         fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
1404         fabric->tf_ops.tpg_release_fabric_acl =
1405                                         &tcm_loop_tpg_release_fabric_acl;
1406         fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
1407         /*
1408          * Used for setting up remaining TCM resources in process context
1409          */
1410         fabric->tf_ops.new_cmd_map = &tcm_loop_new_cmd_map;
1411         fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
1412         fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
1413         fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
1414         fabric->tf_ops.close_session = &tcm_loop_close_session;
1415         fabric->tf_ops.stop_session = &tcm_loop_stop_session;
1416         fabric->tf_ops.fall_back_to_erl0 = &tcm_loop_fall_back_to_erl0;
1417         fabric->tf_ops.sess_logged_in = &tcm_loop_sess_logged_in;
1418         fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
1419         fabric->tf_ops.sess_get_initiator_sid = NULL;
1420         fabric->tf_ops.write_pending = &tcm_loop_write_pending;
1421         fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
1422         /*
1423          * Not used for TCM loopback
1424          */
1425         fabric->tf_ops.set_default_node_attributes =
1426                                         &tcm_loop_set_default_node_attributes;
1427         fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
1428         fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
1429         fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
1430         fabric->tf_ops.queue_status = &tcm_loop_queue_status;
1431         fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
1432         fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
1433         fabric->tf_ops.get_fabric_sense_len = &tcm_loop_get_fabric_sense_len;
1434         fabric->tf_ops.is_state_remove = &tcm_loop_is_state_remove;
1435
1436         tf_cg = &fabric->tf_group;
1437         /*
1438          * Setup function pointers for generic logic in target_core_fabric_configfs.c
1439          */
1440         fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
1441         fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
1442         fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
1443         fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
1444         /*
1445          * fabric_post_link() and fabric_pre_unlink() are used for
1446          * registration and release of TCM Loop Virtual SCSI LUNs.
1447          */
1448         fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
1449         fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
1450         fabric->tf_ops.fabric_make_np = NULL;
1451         fabric->tf_ops.fabric_drop_np = NULL;
1452         /*
1453          * Setup default attribute lists for various fabric->tf_cit_tmpl
1454          */
1455         TF_CIT_TMPL(fabric)->tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
1456         TF_CIT_TMPL(fabric)->tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
1457         TF_CIT_TMPL(fabric)->tfc_tpg_attrib_cit.ct_attrs = NULL;
1458         TF_CIT_TMPL(fabric)->tfc_tpg_param_cit.ct_attrs = NULL;
1459         TF_CIT_TMPL(fabric)->tfc_tpg_np_base_cit.ct_attrs = NULL;
1460         /*
1461          * Once fabric->tf_ops has been setup, now register the fabric for
1462          * use within TCM
1463          */
1464         ret = target_fabric_configfs_register(fabric);
1465         if (ret < 0) {
1466                 pr_err("target_fabric_configfs_register() for"
1467                                 " TCM_Loop failed!\n");
1468                 target_fabric_configfs_free(fabric);
1469                 return -1;
1470         }
1471         /*
1472          * Setup our local pointer to *fabric.
1473          */
1474         tcm_loop_fabric_configfs = fabric;
1475         pr_debug("TCM_LOOP[0] - Set fabric ->"
1476                         " tcm_loop_fabric_configfs\n");
1477         return 0;
1478 }
1479
1480 static void tcm_loop_deregister_configfs(void)
1481 {
1482         if (!tcm_loop_fabric_configfs)
1483                 return;
1484
1485         target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
1486         tcm_loop_fabric_configfs = NULL;
1487         pr_debug("TCM_LOOP[0] - Cleared"
1488                                 " tcm_loop_fabric_configfs\n");
1489 }
1490
1491 static int __init tcm_loop_fabric_init(void)
1492 {
1493         int ret;
1494
1495         tcm_loop_cmd_cache = kmem_cache_create("tcm_loop_cmd_cache",
1496                                 sizeof(struct tcm_loop_cmd),
1497                                 __alignof__(struct tcm_loop_cmd),
1498                                 0, NULL);
1499         if (!tcm_loop_cmd_cache) {
1500                 pr_debug("kmem_cache_create() for"
1501                         " tcm_loop_cmd_cache failed\n");
1502                 return -ENOMEM;
1503         }
1504
1505         ret = tcm_loop_alloc_core_bus();
1506         if (ret)
1507                 return ret;
1508
1509         ret = tcm_loop_register_configfs();
1510         if (ret) {
1511                 tcm_loop_release_core_bus();
1512                 return ret;
1513         }
1514
1515         return 0;
1516 }
1517
1518 static void __exit tcm_loop_fabric_exit(void)
1519 {
1520         tcm_loop_deregister_configfs();
1521         tcm_loop_release_core_bus();
1522         kmem_cache_destroy(tcm_loop_cmd_cache);
1523 }
1524
1525 MODULE_DESCRIPTION("TCM loopback virtual Linux/SCSI fabric module");
1526 MODULE_AUTHOR("Nicholas A. Bellinger <nab@risingtidesystems.com>");
1527 MODULE_LICENSE("GPL");
1528 module_init(tcm_loop_fabric_init);
1529 module_exit(tcm_loop_fabric_exit);